Personally I believe in common courtesy, a quality which seems to be seriously lacking in a lot of people these days. I consider myself to be in the "senior" category - that is, I have been around for a while and have learned some things in my time on the planet - and hopefully will be around long enough to learn a whole bunch more.
I have learned that often you can't change a person's belief because sometimes those beliefs is what keeps those people sane - you can't shake the foundations of their beliefs without some consequence. So respect them by having your say respectfully and then backing off - they will either take it on board and modify their beliefs - or they will not. If they will not then there is little point in continuing to harangue them.
I have learned that even the simplest thing, once written down, is open to misinterpretation and misunderstanding - no matter how careful you are to try and make it clear and unambiguous. Respect the fact that other people's life experience will cause them to see things in a different way to yourself - and this is a GOOD thing and is what moves humanity forwards. So be open to the possibility that you may have to explain yourself, or your statements may be challenged and this challenging may be because the other person did not extract your meaning correctly. It could be YOUR fault.
So - in moderation of the forum I believe that the rules as stated above by Reyth should be followed and moderators should moderate accordingly. If people are so ignorant that they can't abide by these rules then I, for one, really don't want to interact with them, to the degree that if it gets bad enough then it could cause me to abandon the forum entirely.
I see no reason why, if somebody wants to challenge another person's point of view, that the challenge cannot be made politely and respectfully.